1. Field of the Invention
This invention relates generally to a combined view and rangefinder for use in cameras having a variable focus objective lens and, more particularly, to a combined view and rangefinder comprising a plurality of snap-fit components and designed to provide a secondary focusing image superposed on a primary viewing image wherein the secondary focusing image may be moved across the primary viewing image in a special manner in correspondence with camera focusing.
2. Background of the Prior Art
Combined view and rangefinders for use in cameras having a variable focus objective lens are well known in the art. Such combined view and rangefinders generally provide a primary viewing image of the scene to be photographed framed in a field of view generally corresponding to the field of view of the camera objective lens as limited by a particular film format. A secondary focusing image having a field of view substantially smaller than the primary viewing image is provided in superposed relation with respect to the primary viewing image and may be moved thereacross in substantial correspondence with camera focusing. The camera is focused by imparting a translational movement to the objective lens along its optical axis while simultaneously effecting a corresponding movement of the secondary focusing image across the primary viewing image. The camera assumes a focused condition with respect to a particular scene to be photographed when the secondary focusing image is moved into direct coincidence with the primary viewing image.
Such combined view and rangefinders generally provide for movement of the secondary focusing image either vertically or horizontally across the field of view of the primary image thus making it difficult to focus on scenes having predominately vertical or horizontal lines. In addition, such combined view and rangefinders generally provide for the secondary focusing image to be centered for movement about the geometric center for the field of view of the primary viewing image thereby resulting in most photographers framing a human photographic subject about the geometric center of the camera field of view. Such framing of human photographic subjects, however, is esthetically undesirable. It is generally preferable to frame the head of a human photographic subject above the geometric center of the field of view. Since the field of view directly corresponds to the film format, this results in the head of a human photographic subject being in the upper half of the photograph which is esthetically preferable to the head of the human photographic subject being located in the exact center of the photograph. In addition, such combined range and viewfinders are generally critically toleranced resulting in a complicated and expensive assembly procedure.
Therefore, it is a primary object of this invention to provide a combined view and rangefinder for use in cameras having a variable focus objective lens wherein a secondary focusing image is provided for superposed oblique movement across a primary viewing image of the scene to be photographed to facilitate focusing under conditions wherein the scene to be photographed is composed primarily of vertical and/or horizontal lines.
It is a further object of this invention to provide a combined view and rangefinder for use in cameras having a variable focus objective lens wherein a secondary focusing image is provided for superposed movement along a path above the geometric center of a primary viewing image thereby facilitating the framing of human photographic subjects.
It is a further object of this invention to provide a combined view and rangefinder for use in cameras having a variable focus objective lens wherein the combined view and rangefinder comprises a plurality of non-critically toleranced components which may be easily and economically snap-fitted together to provide a combined view and rangefinder module which in turn may be calibrated apart from its associated camera and thereafter snap-fitted into the particular camera for which it is intended to be used.
Other objects of the invention will in part be obvious and will in part appear hereinafter. The invention accordingly comprises the mechanism and system possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure.